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arXiv · 1112.4004

Condensate Fraction in Neutron Matter

Luca Salasnich
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Abstract

We study the Bose-Einstein condensation of fermionic pairs in the uniform neutron matter by using the concept of the off-diagonal long-range order of the two-body density matrix of the system. We derive explicit formulas for the condensate density $\rho_c$ and the condensate fraction $\rho_c/\rho$ in terms of the scaled pairing energy gap $\Delta/\epsilon_F$, where $\epsilon_F$ is the Fermi energy. We calculate the condensate fraction $\rho_c/\rho$ as a function of the density $\rho$ by using previously obtained results for the pairing gap $\Delta$. We find the maximum condensate fraction $(\rho_c/\rho)_{max}= 0.42$ at the density $\rho=5.3\cdot 10^{-4}$ fm$^{-3}$, which corresponds to the Fermi wave number $k_F= 0.25$ fm$^{-1}$.

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Luca Salasnich. 2011-12-17. Condensate Fraction in Neutron Matter. https://doi.org/10.1103/physrevc.84.067301

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